Storm Forecast
Valid: Mon 09 Jun 2008 06:00 to Tue 10 Jun 2008 06:00 UTC
Issued: Sun 08 Jun 2008 19:36
Forecaster: GROENEMEIJER

SYNOPSIS

The main jet stream is located over northern Europe meandering near 60 N. South of the associated baroclinic zone, the air is moderately warm across most of Europe, with the exception of the Iberian peninsula. There, a mid/upper-level low over the Spanish highlands should remain approximately stationary.

DISCUSSION

...SE Finland, S Russian Karelia and parts of the Leningrad, Novgorod, Vologda, Tver, Yaroslavl, Vladimir, Kostroma and Ivanovo Oblasts...

An intense mid/upper-level vorticity maximum initally over the southern Gulf of Botnia moves across southern Finland to near Nizhny Novgorod during the forecast period. A strongly-forced convective line will likely be ongoing over southern Finland in the morning and race eastward towards St. Petersburg onward towards Yaroslavl during the day. Regarding the severe threat, strong low-level shear will likely compensate the weak instability. On passage of the convective line, gusts exceeding 25 m/s are locally expected. In addition, a few short-lived tornadoes are possible.

...S and E France...

Rather widespread thunderstorms are expected to develop early in the afternoon as solar heating aids in the formation of up to 1000 J/kg MLCAPE. Weak wind shear will limit the chances of storm organization. Nevertheless, a few local hail events with stones approaching the 2 cm severe limit are possible. Additionally, local flash flooding can occur especially in S France.
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